Carmel Clay Schools Superintendent Nicholas Wahl has resigned after spending three months on paid leave while the school board conducted a review of district leadership.

The resignation is effective immediately, the district announced in a statement Friday evening.

"The Board has concluded that a change in leadership is in the best interest of the school corporation," the statement said. "The Board believes that Dr. Wahl's approach and leadership style are not consistent with the Board's vision. The board and Dr. Wahl have mutually agreed to sever their relationship."

The statement did not elaborate further, and said the board will not comment publicly on personnel matters.

"Indiana law provides public employees with certain privacy rights regarding their employment relationship," the statement said.

Wahl was under contract through June 30, 2022. Under the resignation agreement, he will receive his salary and partial benefits through June 30, but will not receive any incentive compensation for the 2017-18 year, the district said.

Wahl, who was hired in 2013, would make $209,000 this year, according to his amended contract. The district also was providing him free gas and a "vehicle allowance" of $700 per month.

The announcement Friday did not mention Human Resource Director Corrine Middleton, who was also on paid leave. The superintendent is the only employee who reports directly to the school board, so Middleton's employment will be decided by district administrators. As of the last public board meeting, she was still on paid leave.

Wahl's resignation follows four closed-door executive sessions in November and December where the board discussed "job performance."

During the review, the district remained tight-lipped about the circumstances that launched the board's investigation, but board President Layla Spanenberg told IndyStar in October it included Wahl and Middleton's relationship.

"It's part of the review," she said at the time. "We have policies, and we have contracts, and so whatever we have stated within policy or contracts is the standard within which we hold all of our employees."

Wahl's contract lists "immorality" as one of four grounds for potential termination. In the contract, immorality is defined as "conduct objectively and materially offensive to the moral standards of the CCS community."

It remains unclear whether their relationship was the sole reason the administrators were placed on leave.

Middleton came to the district after Wahl. She was hired as assistant HR director in October 2015 and promoted to HR director in July 2016.

During his tenure in Carmel, Wahl has focused on student-centered learning and pushed for a more holistic approach to working with kids by focusing on their social and emotional well-being. Earlier this year, he publicly campaigned to help Carmel pass an operational referendum that will bring in about $14 million per year.

Previously, he was superintendent of two districts in Illinois: Hinsdale Township High School District 86 and Community Unit School District 201. Wahl graduated from Indiana University.

The board said it will begin searching for a new superintendent immediately and hopes to have a person in place by July 1.